UPD75P3116 NEC, UPD75P3116 Datasheet - Page 14

• Manufacturer Part Number: UPD75P3116
• Description: 4-BIT SINGLE-CHIP MICROCONTROLLER
• Manufacturer: NEC

14
4.2 Setting of Stack Bank Selection (SBS) Register
Use the stack bank selection register to switch between the Mk I mode and Mk II mode. Figure 4-1 shows the format of
the stack bank selection register.
The stack bank selection register is set using a 4-bit memory manipulation instruction. When using the Mk I mode, be
sure to initialize the stack bank selection register to 100XB
be sure to initialize it to 000XB
Note Set the desired value for X.
Caution SBS3 is set to “1” after RESET input, and consequently the CPU operates in the Mk I mode. When using
Address
F84H
SBS3 SBS2 SBS1 SBS0
instructions for the Mk II mode, set SBS3 to “0” and set the Mk II mode before using the instructions.
3
2
1
Figure 4-1. Format of Stack Bank Selection Register
Note
0
.
Stack area specification
Mode selection specification
Symbol
SBS
0
0
1
1
0
0
1
Be sure to enter “0” for bit 2.
Mk II mode
Mk I mode
0
1
0
1
Memory bank 0
Memory bank 1
Setting prohibited
Note
at the beginning of the program. When using the Mk II mode,
PD75P3116